1. Field of the Invention
This invention relates to a head slider, and more particularly, to a head slider, which floats above a rotating medium.
In an information memory storage device that has a medium rotatable at a high speed, a carriage having a head slider at an end thereof and a magnetic circuit rotating the carriage in opposite directions, it is required to further increase a density of record on the medium. In order to increase the record density of the medium, it is necessary to decrease a glide height of the head slider.
2. Description of the Related Art
A conventional head slider 10 is shown in FIG. 1. FIG. 1 shows a status that the conventional head slider is under writing or reading a record. A hard disk 20 rotates at a high speed and the head slider 10 floats above the hard disk 20 with a distance a due to air flow 25 induced by a high speed rotation of the hard disk 20. In addition, in a stop mode, the head slider 10 touches the surface of the hard disk 20.
The hard disk 20 comprises a magnetic layer 22 on the surface of the substrate 21 and a lubrication layer 23 having a thickness of several nanometers on the surface thereof. The lubrication layer 23 is formed so as to decrease a friction with the head slider 10 at the time of starting rotation of the hard disk 20, and to improve the durability of the hard disk 20.
The lubrication layer 23 is formed by applying a lubricant, and thereafter being processed by UV irradiation. A main chain of the lubricant is xe2x80x94(CF2-CF20)n-(CF2-0)m-, and a terminal group of the lubricant is Fomblin Zdol(Ausimont) family.
The head slider 10 comprises a head slider body 11 made from ceramics and a magnetic head part 12 formed in the posterior-extremity surface 11a of the head slider body 11. A slider surface 13, which faces the hard disk 20, corresponds to a surface 11b on which the ceramics of the head slider body 11 is exposed.
In the combination of the above-mentioned head slider 10 and the hard disk 20, the floating distance a is about 5 nanometers. The floating distance a is a height of the head slider 10 from the hard disk 20. 5 nanometers is the lowest limit and it is difficult to make the floating distance smaller than 5 nanometers.
A cause of difficulty in reducing the floating distance is considered to be an adhesion between the slider surface 13 of the head slider 10 and the lubrication layer 23 of the hard disk 20 due to the lubricant of the lubrication layer 23 of the hard disk 20 being transferred to the slider surface 13 of the head slider 10.
As a method for preventing a transfer of the lubricant of the lubrication layer 23 of the hard disk 20 to the slider surface 13 of the head slider 10, JP, 6-64869, A discloses a composition of an organic silicone functional group layer which is chemically bonded to a surface of the head slider.
However, since the organic silicone functional group layer has characteristics of generating gas, the generated silicone gas enters between a hard disk and a head slider, which may result in occurrence of a risk of head crash.
It is a general object of the present invention to provide a head slider and an information memory storage device which solve the above-mentioned problems.
A more specific object of the present invention is to reduce the glide height of the head slider to the hard disk by a distance of sub-nano-orders without adhesion of lubricant layers of the head disk and the medium to each other.
In order to achieve the above-mentioned object, there is provided according to one aspect of the present invention a head slider for recording and playing back signals on a medium while floating on the medium, comprising:
a head slider body; and
a lubrication layer on a slider surface of the head slider body,
wherein a lubricant of the lubrication layer has a main chain structure the same as a main chain structure of a lubricant of a lubrication layer of the medium; and
a terminal group has a structure different from a structure of a terminal group of the lubricant of the lubrication layer of the medium.
Additionally, in the head slider according to the present invention, the main chain of the lubricant of the lubrication layer of the head slider body may be xe2x80x94(CF2-CF20)n-(CF2-0)m-;
the terminal group of the lubricant of the lubrication layer of the head slider body may be selected from a group consisting of Fomblin Zdol family, Fomblin AM 3001(Ausimont) family, Amine family, MORESCO PHOSFANOL(matsumura Oil Research Cort.) family, and Fomblin Tetraol(Ausimont) family; and
the terminal group of the head slider body may be different from the terminal group of the lubricant of the lubricant layer of the medium.
In order to achieve the above-mentioned object, there is also provided according to another aspect of the present invention, an information memory storage device comprising, within a housing having a base, a rotatable medium, a carriage having a head slider at an end thereof, and a magnetic circuit which rotates the carriage in opposite directions, wherein the medium including:
a substrate;
a magnetic layer on the substrate; and
a lubrication layer on a surface of the medium,
wherein the head slider has a head slider body; and
a lubrication layer on a slider surface of the head slider body,
wherein a lubricant of the lubrication layer has a main chain structure the same as the main chain structure of the lubricant of the lubrication layer of the medium and
a terminal group having a structure different from the structure of the terminal group of the lubricant of the lubrication layer of the medium.
Additionally, in the information memory storage device according to the present invention, a main chain of the lubricant of the lubrication layer of the medium may be xe2x80x94(CF2-CF20)n-(CF2-0)m-; and
a terminal group may be selected from a group consisting of Fomblin Zdol family, Fomblin AM 3001 family, Amine family, MORESCO PHOSFANOL family, and Fomblin Tetraol family;
wherein a main chain of the lubricant of the lubrication layer of the head slider may be xe2x80x94(CF2-CF20)n-(CF2-0)m-;
a terminal group is selected from a group consisting of Fomblin Zdol family, Fomblin AM 3001 family, Amine family, MORESCO PHOSFANOL family, and Fomblin Tetraol family; and
the terminal group structure is different from the terminal group of the lubricant of the lubrication layer of the medium.
Additionally, in the information memory storage device according to the present invention, the lubricant of the lubrication layer of the medium has a structure in which X1P(Dow Chemical Company) may be added to Fomblin Zdol family; and
the terminal group of the lubricant of the lubrication layer of the head slider is selected from a group consisting of Fomblin AM 3001 family, Amine family, MORESCO PHOSFANOL family, and Fomblin Tetraol family.
Additionally, in the information memory storage device according to the present invention, the terminal structure of the lubricant of the lubrication layer of the head slider may be Fomblin AM 3001 family.
According to the present invention, the structure of the terminal group of the lubricant of the lubrication layer of the head slider is different from the structure of the terminal group of the lubricant of the medium. Thus, the adhesion does not occur between the lubrication layer of the head slider and the lubrication layer of the medium. As a result, the glide height of the head slider to the medium is reduced by a distance of sub-nano-orders as compared with a case in which no lubrication layer is provided on the head slider and another case in which the same terminal group is provided to the lubrication layer of the hard disk. Thus, the floating height of the head slider to the medium can be decreased. Then, signals can be recorded on the medium in a high density.
In addition, the lubricant of the lubrication layer of the head slider and the lubricant of the lubrication layer of the medium have no characteristics of generating gas. So, the increase of the occurrence of a risk of head crash can be prevented even though the floating height of the head slider to the medium become small.
Further, the structure of the terminal group of the lubricant of the lubrication layer on the medium has a structure in which X1P is added to Fomblin Zdol family, whereas the terminal group of the lubricant of the lubrication layer on the head slider is Fomblin AM 3001 family. Thus, the floating height of the head slider to the medium can be decreased, and signals can be recorded on the medium in a high density.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.